<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>检查⼀个数是否为整数</title>
</head>
<body>
    
</body>
</html>
<script>
   var arr = prompt('请输入数字');
   var Arr = Number(arr);
   if(Number.isInteger(Arr)){
    alert('是整数')
   } else{
    alert('不是整数')
   }
</script>